Pneumatically operated circuit breaker having pneumatically assisted arc interrupting means



Jan. 5, 1960 A. s. CASWELL 2,920,170 PNEUMATICALLY OPERATED CIRCUITBREAKER HAVING PNEUMATICALLY ASSISTED ARC INTERRUPTING MEANS Filed Oct.11, 1957 2 Sheets-Sheet 1 l If i INVENTOR. file/#0! J? (III/11 Jan. 5,1960 Filed Oct. 11, 1957 A. s. CASWELL 2,920,170 PNEUMATICALLY OPERATEDCIRCUIT BREAKER HAVING PNEUMATICALLY ASSISTED ARC INTERRUPTING MEANS 2Shasta-Sheet 2 INVENTOR. Her/m? J. (IQ/Will United States PatentPNEUMATICALLY OPERATED CIRCUIT BREAKER HAVING PNEUMATICALLY ASSISTED ARCIN- TERRUPTING MEANS Arthur S. Caswell, Glenside, Pa., assignor to I-T-ECircuit Breaker Company, Philadelphia, Pa., a corporation ofPennsylvania Application October 11, 19 57, Serial No. 689,691 Claims.01. 200-148) This application relates to circuit breakers in general andmore particularly to an air magnetic type circuit breaker which ispneumatically operated between its open and closed positions and inwhich a pneumatic assist is added to the conventional magnetic type arcinterrupting means.

Attempts have been made to improve the interrupting characteristics ofair magnetic type circuit breakers by utilizing a puffer device whichdirected a mere puff of air toward the breaker contacts as they wereparted. This puff of air acted merely to transfer the are from thestationary contacts to a runner of the arc chute. The puff wasrelatively small, being generated by the opening motion of the bridge,and diminished rapidly as the distance between the parted contactsincreased. A

At high current interruption the effect of the puff was negligible sincea strong magnetic field of the current served to rap-idly draw the arcinto the chute and transfer the arc to the runners. It was at relativelylow currents that the puffer was of value in transferring the arc to therunner. I 9

However, the gas generated by the puffer device was ineffective to drivethe are deeply into the arc chute or cool the are after it had beendriven there.

The novel circuit breaker of the instant invention is of the airmagnetic type which is provided with a pneumatic system. This pneumaticsystem furnishes both the opening and closing power for the circuitbreaker contacts and in addition furnishes a blast of gas which assiststhe magnetic arc interrupting means and thereby increases theinterrupting rating of the circuit breaker. The pneumatic systemreferred to is gas stored in a tank at a high pressure of approximately100 psi. and is utilized for complete operation of the circuit breaker,that is, closing, opening, trip free operation and are interruption. Arcinterruption is assisted by subjecting the arc to a high pressure airblast for the entire opening motion of the bridge so that the gas willdrive the are more deeply into the chute and also cool the arc in theprocess.

My novel interrupting arrangement results in a shortening of arcing timeespecially at low currents thereby enabling the rating of theinterrupter to be increased. The pneumatic assist also permits areduction in the size of the conventional type are chute employing aplurality of parallel plates and a magnetic means. Further, thepneumaticsystem enables the circuit breaker bridge to be of a simpleconstruction and also increases the current carrying capacity thereof.

Accordingly, a primary object of the instant invention is to provide anovel air magnetic type circuit breaker which is pneumatically operatedand in which an air blast is utilized for are interruption. Anotherobject is to providea novel circuit breaker which is pneumaticallyoperated between its open and closed positions aswell as beingpneumatically operated trip free.

Still another object is to provide a pneumatic means,

as an assist to the conventional arc interrupting means of an airmagnetic breaker, which acts on the arc while it is in the arc chute.

A further object is to provide a novel circuit breaker utilizing asource of high pressure gas for operation of the circuit breakercontacts as well as to provide a blast directed at the are formed duringcurrent interruption while the arc is in the arc chute of the magneticarc interrupting means.

A still further object is to provide a novel circuit breakerconstruction which eliminates the necessity for opening or closingsprings as well as costly and critical latches for trip free operation.

Yet another object is to provide a hollow light weight current carryingbridge whereon the movable circuit breaker contacts are mounted anddirect a gas blast through the bridge during circuit interruption toplay on the portion of the arc in the arc chute.

These as well as other objects of the instant invention will becomereadily. apparent after reading the following description of theaccompanying drawings in which: 7

Figures 1 and 2 are schematic representations of my novel circuitbreaker shown in a partially sectioned side elevation. In Figure l thecircuit breaker contacts are in engagement while in Figure 2 the circuitbreaker contacts are disengaged.

Figure 3 is a wiring diagram of the control circuits for the novelcircuit breaker of Figures 1 and 2.

Referring to the figures, circuit breaker 10 comprises an upper 11 and alower 12 stationary contact both secured to and suitably insulated fromcircuit breaker frame 13. Bridge 14 is a hollow member pivotally mountedat 15 to lower stationary contact 12. Upper stationary contact 11includes stationary arcing contact 16 and pivotally mounted maincarrying contact 17. Bridge 14 carries movable main contact 19 andmovable arcing contact 18 which is biased in a clockwise direction aboutpin 21 by means of spring 20 so that on circuit closing arcing contacts16, 18 will engage before main contacts 17, 19 and on circuit openingarcing contacts 16, 18 will disengage after main contacts 17, 19 haveparted. Contact pressure is maintained in accordance with magneticblow-on principles well known in the circuit breaker art.

Bridge 14 is operated between the closed and opened positions of Figures1 and 2 respectively by means of operating mechanism through togglelinks 22, 23 which are interconnected by pin 24 at one of theirrespective ends to form the knee of a toggle. The other end of link 22is keyed to stationary operating shaft 25 while the other end ofinsulating link 23 is pivotally secured at 26 to insulating bracket 27which is affixed to bridge 14 in a suitable manner.

Arc extinguishing means 30 is of the conventional air magnetic typefully described in copending application Serial No. 545,956, filedNovember 9, 1955, and assigned to the assignee of the instant invention.Means 30 includes a plurality of spaced parallel arc plates, whichformare chute 31, and coils 32, 33 wound around core 34 whichestablishes a magnetic field in association with arc chute 31. Jump gap35 is provided to transfer the are drawn between contacts 16, 18 to arerunners 36, 37 where the arc may be effectively acted upon by themagnetic field established by coils 32, 33 which drives the arc upwardin are chute 31 where the arc is required to follow a tortuouspath andis thereby elongated and cooled until it is finally distinguished.

v Operating mechanism 100 includes operating valve or fluid motor 101comprising cylinder 102 and piston 103 slidably disposed in cylinder102. Rod 104 is secured to piston 103 and extends through end 105 ofcylinder 102 stored at high pressure in tank 99.

.upon the are formed between the arc runners 36, 37. this manner theconventional air magnetic interrupter ,means 30 is assisted inextinguishing the are by a strong and is pivotally secured at 106 tocrank 107 which in turn'is keyed to main operating shaft 25. Operatmgvalve 101 is pneumatically controlledby means of gas Closing 110 andopening 111 valves control the flow of high pressure gas to operatingvalve 101 with control .valve 120 being interposed therebetween for thepurpose tionship spindles 124126 which are closely fitted to the insidediameter of cylinder 121.

. Rod 123 extends through end 127 of cylinder 121 and .has securedthereto protrusion 128 which is operatively positioned to engage proplatch 130 in order to permit circuit breaker to be opened. Prop latch130 is pivotally secured to stationary pin 131 and is biased thereaboutin a counterclockwise direction by means of a compression spring 132.Stop 133 is suitably positioned to limit the counterclockwise rotationof prop latch 130 and thereby establish its latching position whereinend 134 thereof is in engagement with latch roller 135 which is freelymounted at pin 106.

With circuit breaker 10 in its closed position of Fig- A ure 1 operationthereof to its open position of Figure 2 Y is initiated by opening ortrip valve 111. High pressure gas from tank 99 now finds a clear passagethrough gas line 141, trip valve 111, and gas line 142 to end 127 ofcylinder 121 where the gas acts on the right surface of spindle 126thereby forcing operator 122 to the left against biasing spring 143 tothe position indicated in Figure 2.

Operator 122 in moving to the left causes protrusion 128 to engage leg136 of prop latch 130 thereby rotating it in a clockwise directionwhereby end 134 thereof is "free of latch roller 135. spindle 126 blocksclosing exhaust port 145 and spindle In the position of Figure 2 125blocks closing inlet port 146. The high pressure gas flowing throughtrip valve 111 is now conducted through gas line 150, laterally throughcylinder 121, and through gas line 144 to the right hand end ofoperating 'valve piston 103. This will force piston 103 to the left withgases on the left side of piston 103 being forced through gas line 147,laterally through cylinder 121, land finally being discharged throughopening exhaust port 148.

As piston 103 moves to the left it carries with it rod 104 causing crank107 to rotate main operating shaft 25 'in a clockwise direction.

link 22 in a clockwise direction with the knee 24 of the This in turnwill rotate toggle toggle moving to the right and carrying with ittoggle link 23 thereby rotating bridge 14 about its lower end to bringabout disengagement of cooperating main contacts 17, 19 and cooperatingarcing contacts 16, 18 in the proper sequence. of trip valve 111,solenoid operated arc interrupter valve 150 is opened to provide a cleargas passage through gas lines 151 and 152 to the lower end of hollowbridge 14. -Gas line 152 is comprised of a suitable insulating mate-Simultaneously with the operation rial. A portion of the gas passingthrough line 152 will exit at struck out opening 50 at an intermediatepoint between the ends of bridge 14 and being directed to the gapsformed between cooperating contacts 17, 19 and -16, 18 to scavenge thecontact area and assist jump gap 35 in transferring the arc to runner36.

The major portion of the gas entering bridge 14 will exit through theupper end thereof and flow from the lower to the upper end of arc chute31 and act directly In gas blast acting directly on the portion of thearc in chute 31. This will cause the arc to rise more rapidly in thechute 31 thereby bringing about a more rapid distinction thereof.

Operation of circuit breaker 10 to the closed position is initiated bythe operation of closing valve which provides a gas passage from gasline 141 through closing valve inlet port 146. With opening or tripvalve 111 deenergized biasing spring 143 is effective to move operator122 to its rightmost position. Now spindle 124 blocks opening exhaustport 148 and spindle 125 blocks opening inlet port 150 so that highpressure gas flows laterally through cylinder 121, through gas line 147,to the left hand side of piston 103 thereby forcing piston 103 to theright. Gases on the right side of piston 103 are exhausted through gasline 144, laterally through cylinder 121, and finally through closingexhaust port 145.

As piston 103 moves to the right, rod 104 causes rotation of crank 107thereby rotating main operating shaft 25 in a counterclockwise directionwhich in turn rotates toggle link 22 counterclockwise. Knee 24 moves tothe left carrying with it one end of link 23 and forcing the other endthereof upward so that bridge 14 will rotate counterclockwise aboutpivot 15 thereby closing the circuit breaker 10. As rod 104 is beingmoved to the right, roller 135 engages surface 151 thereby rotating proplatch in a clockwise direction against its bias 132 until roller clearsend 134 at which time biasing spring 132 rotates latch 130 to itslatching positions thereby maintaining circuit breaker 10 closed.

Referring more particularly to Figure 3, control circuit 200 comprises afirst and second parallel path extending between terminals 201, 202 ofcontrol voltage source 203. The first series path begins at terminals201 'of coil 211 is connected to terminal 202 through the parallelcombination of normally closed contacts 213 and normally open contacts214. Normally open switch contacts 212 are paralleled by the normallyopen contacts 215 of a conventional type overcurrent device (not shown)commonly associated with circuit breakers of this type.

A series circuit comprising normally open contacts 216 and solenoid coil250, which controls the operation of valve 150, is connected fromterminal 202 to the juncture between solenoid coil 211 and openingswitch 212.

Another pair of normally open contacts 217 are connected between thelast named juncture and the juncture between closing switch contacts 204and solenoid coil 210. Contacts 205, 214 and 217 are associated with airoperated switch 220 connected to gas line 142. Contacts 213, 216 areassociated with an auxiliary switch (not shown) of well known type.Contacts 206 are associated with another switch (not shown) which isoperated when the circuit breaker reaches its closed position so thatclosing coil 210 will not be continuously energized even though thecontacts of closing switch 204 are engaged.

With the circuit breaker 10 in the open position of Figure 2 theoperation of closing switch 204 will energize closing solenoid coil 210so that piston 103 is. operated to the right as hereinbefore explained.When the circiut breaker reaches its fully closed position concoil :211through auxiliary switch contacts 213. With trip valve 111 in the openposition high pressure gas in line 142 will operate switch 220 therebysimultaneously closing contacts 214 and 217 and opening contacts 205.This will immediately deenergize closing coil 210 with tripping valve111 assuming complete control. Pressure released through line 142 drivesoperator 122 to the left against the bias of spring 143 with spindle 125mechanically blocking the high pressure gas supply, to the L.H. end ofcylinder 121 and fully venting it to the atmosphere through openingexhaust port 148 so that the opening of circuit breaker may proceed inthe manner previously set forth. If closing switch 204 continues toremain closed a continuous current path extends from the terminal 201through switch 204, contacts 217, trip coil 211, and contacts 214 toterminal 202 but the current path through closing coil 210 is broken toprevent pumping.

The auxiliary switch (not shown) with which contacts 213 and 216 areassociated is operatively connected to operating shaft 25, in a mannerwell known to the art, such that contacts 216 are closed when circuitbreaker 10 is in the closed position of Figure 1. With circuit breaker11 closed and trip coil 211 energized, valve 150 is opened sincesolenoid 250 and closed contacts 213 are in parallel with trip coil 211and closed contacts 213. Contacts 216 are adjusted to open atapproximately the /3 point of the breaker opening stroke with the exactadjustment being determined by tests and the dictates of economy.Contact 213 of the auxiliary switch open when circuit breaker 10 is inthe open position of Figure 2.

Thus, I have provided a novel air magnetic type circuit breaker which ispneumatically operated and in which an air blast is utilized for areinterruption. This construction eliminates the necessity for providingopening springs and costly critical latches characteristic of most tripfree operating mechanisms. The pneumatic operation also eliminates thenecessity for a puffer device yet achieves efiicient arc transfer to therunners of the arc extinguishing means.

In the foregoing, I have described my invention only in connection withpreferred embodiments thereof. Many variations and modifications of theprinciples of my invention within the scope of the description hereinare obvious. Accordingly, I prefer not to be bound by the specificdisclosure herein but only by the appending claims.

I claim:

1. An air magnetic type circuit breaker being comprised of a pair ofcooperating contacts, an operating mechanism operatively connected tomove said cooperating contacts between an engaged and a disengagedposition, and magnetic arc interrupting means operatively positioned toreceive andextinguish an are drawn between said cooperating contacts asthey are moved from said engaged to said disengaged position; pneumatic.means operatively connected to said operating mechanism and operativelypositioned to subject said are to a gas blast from said pneumatic meanswhile said arc is received by said magnetic arc interrupting means; ahollow movable bridge having a first of said cooperating contactssecured thereto near a first end thereof; said pneumatic means beingoperatively connected to said bridge near a second end thereof with saidgas blast being directed by said bridge into said magnetic arcinterrupting means; and opening in said bridge intermediate the endsthereof; said gas blast having an intensity which is independent of thespeed of movement of said bridge; means at the edge of said openingconstructed to direct a small portion of said gas blast at the areaoccupied by said cooperating contacts when in said engaged position.

2 An air magnetic type circuit breaker being comprised of a pair ofcooperating contacts, an operating mechanism operatively connected tomove said cooperating contacts between an engaged and a disengagedposition, and magnetic arc interrupting means operatively positioned toreceive and extinguish an are drawn between said cooperating contacts asthey are moved from said engaged to said disengaged position; one ofsaid pair of cooperating contacts being fixedly mounted; pneumatic meansoperatively connected to said operating mechanism and operativelypositioned to subject said arc to a gas blast from said pneumatic meanswhile said are is received by said magnetic arc interrupting means; saidpneumatic means including a pneumatically operated control means, apneumatically operated operating means, and means providing fluid guidemeans between said control means and said operating means; said controlmeans operatively connected through said operating mechanism to saidoperating mechanism for operation thereof between a first positionwherein said cooperating contacts are disengaged and a second positionwherein said contacts are engaged; said control mechanism beingpneumatically operated to said first position when said circuit breakeris being closed on a fault for trip free operation of said operatingmechanism.

3. An air magnetic type circuit breaker being comprised of a pair ofcooperating contacts, an operating mechanism operatively connected tomove said cooperating contacts between an engaged and a disengagedposition, and magnetic arc interrupting means operatively positioned toreceive and extinguish an are drawn between said cooperating contacts asthey are moved from said engaged to said disengaged position; one ofsaid pair of cooperating contacts being fixedly mounted; a gas operatedmeans operatively connected to said operating mechanism; said gasoperated means including a gas operated control means operable between afirst and a second position; a first valve and a second valveoperatively connected between said gas operated control means and asource of high pressure gas; said first valve when open permitting gasfrom said source to operate said gas operated control means to saidfirst position wherein said cooperating contacts are disengaged; saidsecond valve when open permitting gas from said source to operate saidgas operated control means to said second position wherein saidcooperating contacts are engaged only when said first valve is closedwhereby said operating mechanism is operated trip free when closing on afault.

4. An air magnetic type circuit breaker being comprised of a pair ofcooperating contacts, an operating mechanism operatively connected tomove said cooperating contacts between an engaged and a disengagedposition, and magnetic arc interrupting means operatively positioned toreceive and extinguish an are drawn between said cooperating contacts asthey are moved from said engaged to said disengaged position; a gasoperated means operatively connected to said operating mechanism andoperable between a first and a second position; a first valve and asecond valve operatively connected between said gas operated means and asource of high pressure gas; said first valve when open permitting gasfrom said source to operate said gas operated means to said firstposition wherein said cooperating contacts are disengaged; said secondvalve when open permitting gas from said source to operate said gasoperated means to said second position wherein said cooperating contactsare engaged only when said first valve is closed; said gas operatedmeans comprising a single operating valve and a control valveoperatively connected between said operating valve and said first andsaid second valves; said operating valve also being operativelyconnected to said operating mechanism; said control valve providing aportion of an unobstructed first gas passage between said source andsaid operating valve when said first valve is open; said control valveproviding a portion of an un- 7 obstructed second gas passage betweensaid source and said operating valve only when said second valve is openand said first Valve is closed.

5. An air magnetic type circuit breaker being comprised of a pair ofcooperating contacts, an operating mechanism operatively connected tomove said cooperating contacts between an engaged and a disengagedposition, and magnetic arc interrupting means operatively positioned toreceive and extinguish an are drawn between said cooperating contacts asthey are moved from said engaged to said disengaged position; a gasoperated means operatively connected to said operating mechanism andoperable between a first and a second position; a first valve and asecond valve operatively connected between said gas operated means and asource of high pressure gas; said first valve when open permitting gasfrom said source to operate said gas operated means to said firstposition wherein said cooperating contacts are disengaged; said secondvalve when open permitting gas from said source to operate said gasoperated means to said second position wherein said cooperating contactsare engaged only when said first valve is closed; said gas operatedmeans comprising an operating valve and a control valve operativelyconnected between said operating valve and said first and said secondvalves; said operating valve also being operatively connected to saidoperating mechanism; said control valve providing a portion of anunobstructed first gas passage between said source and said operatingvalve when said first valve is open; said control valve providing aportion of an unobstructed second gas passage between said source andsaid operating valve only when said second valve is open and said firstvalve is closed; said operating valve including a first cylinder and apiston closely fitted to said first cylinder; said first and second gaspassages communicating with a first and a second end respectively ofsaid cylinder; said cooperating contacts being disengaged when saidpiston is at said second end and being engaged when said piston is atsaid first end.

6. An air magnetic type circuit breaker being comprised of a pair ofcooperating contacts, an operating mechanism operatively connected tomove said cooperating contacts between an engaged and a disengagedposition, and magnetic arc interrupting means operatively positioned toreceive and extinguish an are drawn between said cooperating contacts asthey are moved from said engaged to said disengaged position; a gasoperated means operatively connected to said operating mechanism andoperable between a first and a second position; a first vaive and asecond valve operatively connected between said gas operated means and asource of high pressure gas; said first valve when open permitting gasfrom said source to operate said gas operated means to said firstposition wherein said cooperating contacts are disengaged; said secondvalve when open permitting gas from said source to operate said gasoperated means to said second position wherein said cooperating contactsare engaged only when said first valve is closed; said gas operatedmeans comprising an operating valve and a control valve operativelyconnected between said operating valve and said first and said secondvalves; said operating valve also being operatively connected to saidoperating mechanism; said control valve providing a portion of anunobstructed first gas passage between said source and said operatingvalve when said first valve is open; said control valve providing aportion of an unobstructed second gas passage between said source andsaid operating valve only when said second valve is open and said firstvalve is closed; said operating valve including a first cylinder and apiston closely fitted to said first cylinder; said first and second gaspassages communicating with a first and a second end respectively ofsaid cylinder; said cooperating contacts being disengaged when saidpiston is at said second end and being engaged when said piston is atsaid first end; said operating valve including a second cylinder and anoperator; said operator being disposed within said second cylinder andbiased in a first direction to a first position when said first gaspassage is blocked;

said operator being operated against the bias to a second position bygas from said source when said first valve is open; said first gaspassage being unobstructed when said operator is in its said secondposition.

7. An air magnetic type circuit breaker being comprised of a pair ofcooperating contacts, an operating mechanism operatively connected tomove said cooperating contacts between an engaged and a disengagedposition, and magnetic arc interrupting means operatively positioned toreceive and extinguish an arc drawn between said cooperating contacts asthey are moved from said engaged to said disengaged position; a gasoperated means operatively connected to said operating mecha nism andoperable between a first and a second posi tion; a first valve and asecond valve operatively connected between said gas operated means and asource of high pressure gas; said first valve when open permitting gasfrom said source to operate said gas operated means to said firstposition wherein said cooperating contacts are disengaged; said secondvalve when open permitting gas from said source to operate said gasoperated means to said second position wherein said cooperating contactsare engaged only when said first valve is closed; said gas operatedmeans comprising an operating valve and a control valve operativelyconnected between said operating valve and said first and said secondvalves; said operating valve also being operatively connected to saidoperating mechanism; said control valve providing a portion of anunobstructed first gas passage between said source and said operatingvalve when said first valve is open; said control valve provid ng aportion of an unobstructed second gas passage between said source andsaid operating valve only when said second valve is open and said firstvalve is closed; said operating valve including a first cylinder and apiston closely fitted to said first cylinder; said first and second gaspassages communicating with a first and a second end respectively ofsaid cylinder; said cooperating contacts being disengaged when saidpiston is at said second end and being engaged when said piston is atsaid first end; said operating valve including a second cylinder and anoperator; said operator being disposed within said second cylinder andbiased in a first direction to a first position when said first gaspassage is blocked; said operator being operated against the bias to asecond position by gas from said source when said first valve is open;said first gas passage being unobstructed when said operator is in itssaid second position; said second cylinder including a first and asecond port; said first port being connected to the first end of saidfirst cylinder when said operator is in its said first position and saidsecond port being connected to the second end of said first cylinderwhen said operator is in its said second position.

8. An air magnetic type circuit breaker being comprised of a pair ofcooperating contacts, an operating mechanism operatively connected tomove said cooperating contacts between an engaged and a disengagedposition, and magnetic arc interrupting means operatively positioned toreceive and extinguish an are drawn between said cooperating contacts asthey are moved from said engaged to said disengaged position; a gasoperated means operatively connected to said operating mechanism andoperable between a first and a second position; a first valve and asecond valve operatively connected between said gas operated means and asource of high pressure gas; said first valve when open permitting gasfrom said source to operate said gas operated means to said firstposition wherein said cooperating contacts are disengaged; said secondvalve when open permitting gas from said source to operate said gasoperated means to said second position wherein said cooperating contactsare engaged only when said first valve is closed; said gas Operatedmeans comprising an operating valve and a control valve operativelyconnected between said operating valve and said first and said secondvalves; said operating valve also being operatively connected to saidoperating mechanism; said control valve providing a portion of anunobstructed first gas passage between said source and said operatingvalve when said first valve is open; said control valve providing aportion of an unobstructed second gas passage between said source andsaid operating valve only when said second valve is open and said firstvalve is closed; said operating valve including a first cylinder and apiston closely fitted to said first cylinder; said first and second gaspassages communicating with a first and a second end respectively ofsaid cylinder; said cooperating contacts being disengaged when saidpiston is at said second end and being engaged when said piston is atsaid first end; said operating valve including a second cylinder and anoperator; said operator being disposed within said second cylinder andbiased in a first direction to a first position when said first gaspassage is blocked; said operator being operated against the bias to asecond position by gas from said source when said first valve is open;said first gas passage being unobstructed when said operator is in itssaid second position; said second cylinder including a first and asecond port; said first port being connected to the first end of saidfirst cylinder when said operator is in its said first position and saidsecond port being connected to the second end of said first cylinderwhen said operator is in its said second position; said operatorincluding a first, a second, and a third spindle; said spindles beingdisplaced along the axis of said operator and operatively connected tomove in unison; said second spindle blocking said first gas passage andsaid third spindle blocking said second port when said operator is inits said first position; said first spindle blocking said first port andsaid second spindle blocking said second gas passage when said operatoris in its said second position.

9. An air magnetic type circuit breaker being comprised of a pair ofcooperating contacts, an operating mechanism operatively connected tomove said cooperating contacts between an engaged and a disengagedposition, and magnetic arc interrupting means operatively positioned toreceive and extinguish an are drawn between said cooperating contacts asthey are'moved from said engaged to said disengaged position; a gasoperated means operatively connected to said operating mechanism andoperable between a first and a second position; a first valve and asecond valve operatively connected between said gas operated means and asource of high pressure gas; said first valve when open permitting gasfrom said source to operate said gas operated means to said firstposition wherein said cooperating contacts are disengaged; said secondvalve when open permitting gas from said source to operate said gasoperated means to said second position wherein said cooperating contactsare engaged only when said tfirst valve is closed; said gas operatedmeans comprising an operating valve and a control valve operativelyconnected between said operating valve and said first and said secondvalves; said operating valve also being operatively connected to saidoperating mechanism; said control valve providing a portion of anunobstructed first gas passage between said source and said operatingvalve when said first valve is open; said control valve providing aportion of an unobstructed second gas passage between said source andsaid operating valve only when said second valve is open and said firstvalve is closed; a third valve operatively connected between said sourceand said magnetic arc interrupting means; said magnetic are interruptingmeans being subjected to a gas blast from said source while said thirdvalve is open.

10. An air magnetic type circuit breaker being comprised of a pair ofcooperating contacts, an operating mechanism operatively connected tomove said cooperating contacts between an engaged and a disengagedposition, and magnetic arc interrupting means operatively positioned toreceive and extinguish an are drawn between said cooperating contacts asthey are moved from said engaged to said disengaged position; a gasoperated means operatively connected to said operating mechanism andoperable between a first and a second position; a first valve and asecond valve operatively connected between said gas operated means and asource of high pressure gas; said first valve when open permitting gasfrom said source to operate said gas operated means to said firstposition wherein said cooperating contacts are disengaged; said secondvalve when open permitting gas from said source to operate said gasoperated means to said second position wherein said cooperating contactsare engaged only when said first valve is closed; said gas operatedmeans comprising an operating valve and a control valve operativelyconnected between said operating valve and said first and said secondvalves; said operating valve also being operatively connected to saidoperating mechanism; said control valve providing a portion of anunobstructed first gas passage between said source and said operatingvalve when said first valve is open; said control valve providing aportion of an unobstructed second gas passage between said source andsaid operating valve only when said second valve is open and said firstvalve is closed; a third valve operatively connected between said sourceand said magnetic arc interrupting means; said magnetic arc interruptingmeans being subjected to a gas blast from said source while said thirdvalve is open; a hollow movable bridge having a first of saidcooperating contacts secured thereto near a first end thereof; saidthird valve being operatively connected to said bridge near a second endthereof with said gas blast being directed by said bridge into saidmagnetic arc interrupting means; said third valve being open forsubstantially all of the time interval during which said cooperatingcontacts are being moved from said engaged to said disengaged positions.

References Cited in the file of this patent UNITED STATES PATENTS1,498,714 Aikman June 24, 1924 2,568,008 Jansson Sept. 18, 19512,597,126 Paterson May 20, 1952 2,680,793 Schneider et al June 8, 19542,816,993 Linde. Dec. 17, 1957

